Ture piercing and expanding plug



July 21, 1931. w BARK 4 1,815,426

TUBE P IERCING AND EXPANDING PLUG Filed Dec. 4. 1929 192062050X:W/LLMMBA RK.

Patented July 21 1931 UNITED STATES PATENT OFFICE l wILLIAu Buzz, onGARY, INDIANA, ASSIGNOR TO. NATIONAL TUBE COMPANY, A

CORPORATION on NEW JnRsEY 'runn PIERGING AND EXPANDING PLUG Applicationfiled December 4, 1929. Serial No. 411,540.

This invention relates to expanding plugs foruse in the manufacture ofseamless tubes and has for its object the rovision of a novel form oftwo-part plug esigned so that the nose portion'which receives the majorportion of the wear may be readily replaced when worn.

Heretofore, plugs of this class have generally been formed in one piecefrom a casting or forging and when worn, the whole plug was necessarilydestroyed.

With the present invention it-is only necessary to replace a very smallpart of the plug when it becomes worn, thus providing a considerablesaving in cost of plugs.

In the drawings- Figure 1 is a sectional view through the forward end ofan expanding bar and plug constructed in accordance with this invention,

the section being taken on the line 1-1 of Figure 2. Figure 2 isatransverse section taken on the line II-'II of Figure 1.

Figure 3 is a transverse section taken on the line III-III of Figure 2.

Referring more particularly to the drawings the numeral 2 designates theplug bar as a whole, which is of ordinary design, and has its forward orplug end reduced, as at 3,

to form a plug supporting spindle which terminates at its rear end 1n ashoulder 4. 'The bar 2 has a central bore 5 to permit the circulation ofa cooling fluid therethrough for controlling the temperature of the bar.

A plug A is removably mounted on the reduced or spindle end 3- of thebar 2'and has its rear end abutting-the shoulder' l. The.

lug A is formed in two parts as will be seen y reference to the drawingsin which the numeral 6 designates the bod portion of the plug while thenumeral 7 esignates a rcmovable nose portion thereof. I

The body ortion 6 of the plug has its-forward end e uced in diameter, asat 8, to receive the rose 7 which is longer than the ortion 8 and hasits forward end exten ing' downwardly in front of the forward end of theplug body, as at 10. The reduced portion 8 terminates at its rear end ina shoulder 9.

The reduced diameter portion 8 of the plug body 6 1s provided withbayonet slots 12 and 13 at diametrically opposite points which areadapted to receive lugs Hand 15, respective: ly, formed integral withand projecting into the bore of the nose 7 at the rear end thereof.

It will be seen that the nose portion 7 of the plug A may be readilymounted on the plug body 6 by alining'the lugs 14 and 15 wlth thegrooves 12 and 13 and then sliding the nose member rearwardly until itsrear- .end engages the shoulder 9. The nose mem- 1 draw the nose fromthe body 6.

Since substantially all of the wear is on the nose of the plugs used inexpanding or otherj wise working seamless tubes the advantage of havingsuch nose portion readily renewable will be appreciated While I haveshown and described one specific embodiment of my invention it will.

be understood that I do not wish to be limited thereto since variousmodifications may be made without departing from the scope thereof, asdefined in the appended claims.

I- claim:

1. The combination with afiplug-bar for seamless tubeinachines havingone end re-' duced forming a plug receiving shank termin-ating in ashoulder, of a plug mounted on said shank andabutting said shoulder,said plug having itslforwar end reduced in diameter to receive aremovable nose, bayonetlike slots formed in said reduced diameter endportion of said plug, and a removable nose member mounted on saidreduced diameter end of said plug, said nose member being provided'withlugs-ada ted to be locked in said ,bayonetdike slots said nose member.

seamless tube machines having one end rey a rotation of' duced forminga-plug receiving shank ter- 1 mma/tmg 111 a shoulder, of a plug mountedon said shank and abutting said shoulder, said plug having its forwardend reduced in diameter, a removable nose on said reduced diameter endof said plug and means for removably locking said nose portion on saidreduced diameter end of said plug.

In testimony whereof, I have hereunto set my hand.

LIAM BARK.

